FI117139B - Production of zinc chemicals from process stream - Google Patents

Description

This invention relates to a process for the preparation of zinc and zinc chemicals. More particularly, the invention relates to a process arrangement for the production of zinc chemicals in a zinc hydrometallurgical process.

Zinc production is often referred to as secondary production. Primary production refers to the various solutions of concentrates and roasts and their treatment by various hydrometallurgy techniques to which the liquid belongs. Secondary production refers to Waelt of various volumes of raw materials such as electric furnace dust; use of galvanizing ash as a raw material.

15

In the primary production of zinc, traditional starting materials, zinc ores, are concentrated, making them blue

if desired, zinc patch. Often from zinc concentrate J

: V. further, a concentrated zinc sulphate solution is produced which * * • for electrolytic production of 20 zinc metals. Current ·: ··: Traditional Primary Zinc Hydrometallurgical Production * * «

In conventional hydrometallurgical production of zinc, a complex solution purification with a final zinc-containing solution is required after the raw material. The electrolytic production of zinc is very ..ΙΓ for impurities. Therefore, it is important to prepare enough · * · • · ♦ II ·! U I * ·.

2

In the leaching step, the zinc is soluble and most of the roast iron is extracted as zinc ferrite, which is insoluble in the law. The solution from neutral leaching contains 5 iron, cadmium, copper, cobalt, nickel, calcium, chlorides.

The solution obtained in neutral leaching is purified by a solution purification process to obtain a suitable solution for the electrolysis of zinc. Leaching usually involves three removal of copper, cobalt and nickel and lastly cadmium.

Zinc-containing sulphate solution obtained from neutral leaching as input to the zinc extraction process. Until recently, liquid-i 15 used in the manufacture of zinc is mainly small-scale pro using secondary raw materials. For example, the patent describes a solution extraction that selectively yields a non-zinc sulfate solution which may even contain a saturated solution. zinc sulphate and one or more of the following: two * 4. 20 trivalent iron, calcium, magnesium, manganese potassium, arsenic, antimony, copper, cadmium, germaniums It is an object of the present invention to provide a novel p-leaching process from the side stream of a 25-type zinc manufacturing process for the production of pure zinc chemicals. The invention was canceled for the use of f * # 3 substituted phosphoric acid or organically substituted from the leaching-digestion electrolysis plant. According to the invention, the extraction process is coupled with the leaching electrolysis process above.

The invention provides considerable advantages. Conventional dissolution electrolysis process production bottleneck in the lysis process. Thus, the solution according to the invention for the production line of zinc chemicals by-products adds value to the production process of the rod. The invention provides an inexpensive process solution 10 for the production of low volume zinc chemicals. The invention comprises a process coupling and arrangement for the preparation of pure zinc soluble vi * «· • i • ·; Figure 1 shows a simplified process diagram of the process for making tin *: *: zinc electrolysis type and ·: ··: the step of making zinc chemicals.

m 9 9 4 * ♦ ♦ ft

In the following, the invention will be described in detail with reference to the accompanying k 25 ": · * A zinc oxide-containing tin 99 9 4 is recovered in zinc for cathodes 16. The electrolyte from which zinc 17 contains considerable sulfuric acid which is re-introduced into concentrated acid leaching. The concentrated acidic solvent is consumed in the reactions. Thus, in addition to the acid to be recycled, the process has 5 amounts of pure acid. In neutral solution, the pH of the solution is not: up. It is prudent to adjust the pH of the neutral leach with fresh h £ acid obtained from concentrated acid leach 18.

According to the invention, a side stream 13 is separated from the main stream 11 of the solution of zinc 10 from neutral leaching, which is conducted in an extraction using diethylhexylphosphoric acid (DEHPA) hexyl) phosphoric acid (D2EHPA). If necessary, the pH of the leaching solution may be raised by means of an extraction solution. Zinc 15 is separated from the organic phase with an acidic solution 21. The raffinate extracted from the extraction contains 1 µl of sulfuric acid and is recycled to the concentrated acid stage

Stripping using pure acid yields a solution of sulfuric acid in which the concentration of zinc can be from 20 to 20. Various pure zinc products can be prepared by methods such as chemical precipitation or shear. * * * «999 9 9999 999 9 9 9 9999 25 • 999 9 9999 999 9 9 9 9

Claims (4)

A process coupling for the preparation of zinc chemicals from a concentrated solution by an extraction method known in the art from a roasting-leaching-electrolysis-type line of primary production after separating part s from solution (11) into a side stream (13) for direct preparation of zinc. 10 A process arrangement according to claim 1, wherein the raffinate (19) produced by the extraction is re-directed to the acid leaching of said roast-leach-electrolysis type proce. The process arrangement according to claim 1, wherein diethyl hexylphosphoric acid di (2-ethylhexyl) phosphoric acid (D2EHPA) is utilized. The process arrangement according to claim 1, wherein at the end of the leaching step, the extruder is raised to a level suitable for extraction by means of a roasting agent. • «« «♦ ·· • t» • »ψ» M »• #« • Ψ · ··· «♦